// 兼容
window.URL = window.URL || window.webkitURL
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia
let HZRecorder = function (stream, config) {
    config = config || {}
    config.sampleBits = config.sampleBits || 8 // 采样数位 8, 16
    config.sampleRate = config.sampleRate || (44100 / 6) // 采样率(1/6 44100)
    let context = new (window.webkitAudioContext || window.AudioContext)()
    let audioInput = context.createMediaStreamSource(stream)
    let createScript = context.createScriptProcessor || context.createJavaScriptNode
    this.source = context.createBufferSource();
    let recorder = createScript.apply(context, [4096, 1, 1])
    let audioData = {
        size: 0, // 录音文件长度
        buffer: [], // 录音缓存
        inputSampleRate: context.sampleRate, // 输入采样率
        inputSampleBits: 16, // 输入采样数位 8, 16
        outputSampleRate: config.sampleRate, // 输出采样率
        oututSampleBits: config.sampleBits, // 输出采样数位 8, 16
        input: function (data) {
            this.buffer.push(new Float32Array(data))
            this.size += data.length
        },
        compress: function () { // 合并压缩
            // 合并
            let data = new Float32Array(this.size)
            let offset = 0
            for (let i = 0; i < this.buffer.length; i++) {
                data.set(this.buffer[i], offset)
                offset += this.buffer[i].length
            }
            // 压缩
            let compression = parseInt(this.inputSampleRate / this.outputSampleRate)
            let length = data.length / compression
            let result = new Float32Array(length)
            let index = 0; let j = 0
            while (index < length) {
                result[index] = data[j]
                j += compression
                index++
            }
            return result
        },
        encodeWAV: function () {
            let sampleRate = Math.min(this.inputSampleRate, this.outputSampleRate)
            let sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits)
            let bytes = this.compress()
            let dataLength = bytes.length * (sampleBits / 8)
            let buffer = new ArrayBuffer(44 + dataLength)
            let data = new DataView(buffer)
            let channelCount = 1// 单声道
            let offset = 0
            let writeString = function (str) {
                for (let i = 0; i < str.length; i++) {
                    data.setUint8(offset + i, str.charCodeAt(i))
                }
            }
            // 资源交换文件标识符
            writeString('RIFF'); offset += 4
            // 下个地址开始到文件尾总字节数,即文件大小-8
            data.setUint32(offset, 36 + dataLength, true); offset += 4
            // WAV文件标志
            writeString('WAVE'); offset += 4
            // 波形格式标志
            writeString('fmt '); offset += 4
            // 过滤字节,一般为 0x10 = 16
            data.setUint32(offset, 16, true); offset += 4
            // 格式类别 (PCM形式采样数据)
            data.setUint16(offset, 1, true); offset += 2
            // 通道数
            data.setUint16(offset, channelCount, true); offset += 2
            // 采样率,每秒样本数,表示每个通道的播放速度
            data.setUint32(offset, sampleRate, true); offset += 4
            // 波形数据传输率 (每秒平均字节数) 单声道×每秒数据位数×每样本数据位/8
            data.setUint32(offset, channelCount * sampleRate * (sampleBits / 8), true); offset += 4
            // 快数据调整数 采样一次占用字节数 单声道×每样本的数据位数/8
            data.setUint16(offset, channelCount * (sampleBits / 8), true); offset += 2
            // 每样本数据位数
            data.setUint16(offset, sampleBits, true); offset += 2
            // 数据标识符
            writeString('data'); offset += 4
            // 采样数据总数,即数据总大小-44
            data.setUint32(offset, dataLength, true); offset += 4
            // 写入采样数据
            if (sampleBits === 8) {
                for (let i = 0; i < bytes.length; i++ , offset++) {
                    let s = Math.max(-1, Math.min(1, bytes[i]))
                    let val = s < 0 ? s * 0x8000 : s * 0x7FFF
                    val = parseInt(255 / (65535 / (val + 32768)))
                    data.setInt8(offset, val, true)
                }
            } else {
                for (let i = 0; i < bytes.length; i++ , offset += 2) {
                    let s = Math.max(-1, Math.min(1, bytes[i]))
                    data.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true)
                }
            }
            return new Blob([data], { type: 'audio/mp3' })
        }
    }
    // 开始录音
    this.start = function () {
        audioInput.connect(recorder)
        recorder.connect(context.destination)
    }
    // 停止
    this.stop = function () {
        recorder.disconnect()
    }
    // 获取音频文件
    this.getBlob = function () {
        this.stop()
        return audioData.encodeWAV()
    }
    // 回放
    this.play = function (audio) {
        console.log(audio)
        audio.src = window.URL.createObjectURL(this.getBlob())
        // console.log(audio)
        // let downRec = document.getElementById('downloadRec')
        // downRec.href = window.URL.createObjectURL(this.getBlob())
        // downRec.download = new Date().toLocaleString() + '.mp3'
        // audio.src = window.URL.createObjectURL(this.getBlob())
        // console.log(audio.src)
    }

    // 上传
    this.upload = function (url, callback) {
        let fd = new FormData()
        fd.append('audioData', this.getBlob())
        let xhr = new XMLHttpRequest()
        /* eslint-disable */
        if (callback) {
            xhr.upload.addEventListener('progress', function (e) {
                callback('uploading', e)
            }, false)
            xhr.addEventListener('load', function (e) {
                callback('ok', e)
            }, false)
            xhr.addEventListener('error', function (e) {
                callback('error', e)
            }, false)
            xhr.addEventListener('abort', function (e) {
                callback('cancel', e)
            }, false)
        }
        /* eslint-disable */
        xhr.open('POST', url)
        xhr.send(fd)
    }
    // 音频采集
    HZRecorder.recorder = recorder;
    // recorder.onaudioprocess = function (e) { //开始处理音频
    //     var buffer = e.inputBuffer.getChannelData(0); //获得缓冲区的输入音频，转换为包含了PCM通道数据的32位浮点数组
    //     // 创建变量并迭代来获取最大的buffer中的音量值
    //     var maxVal = 0;
    //     for (var i = 0; i < buffer.length; i++) {
    //         if (maxVal < buffer[i]) {
    //             maxVal = buffer[i];
    //         }
    //     }
    //     //显示音量值 在这获取到音量值 
    //     // 但是我怎么让外面的test.vue获取到呢
    //     // console.log(maxVal * 10000)
    // };

}
// 抛出异常
HZRecorder.throwError = function (message) {
    // alert(message)
    throw new function () { this.toString = function () { return message } }()
}
// 是否支持录音
HZRecorder.canRecording = (navigator.getUserMedia != null)
// 获取录音机
HZRecorder.get = function (callback, config) {
    if (callback) {
        if (navigator.getUserMedia) {
            navigator.getUserMedia(
                { audio: true } // 只启用音频
                , function (stream) {
                    let rec = new HZRecorder(stream, config);
                    callback(rec)
                }
                , function (error) {
                    switch (error.code || error.name) {
                        case 'PERMISSION_DENIED':
                        case 'PermissionDeniedError':
                            HZRecorder.throwError('用户拒绝提供信息。')
                            break
                        case 'NOT_SUPPORTED_ERROR':
                        case 'NotSupportedError':
                            HZRecorder.throwError('浏览器不支持硬件设备。')
                            break
                        case 'MANDATORY_UNSATISFIED_ERROR':
                        case 'MandatoryUnsatisfiedError':
                            HZRecorder.throwError('无法发现指定的硬件设备。')
                            break
                        default:
                            HZRecorder.throwError('无法打开麦克风。异常信息:' + (error.code || error.name))
                            break
                    }
                })
        } else {
            HZRecorder.throwErr('当前浏览器不支持录音功能。'); return
        }
    }
}

export default  HZRecorder
